extern mod => extern crate

This was previously implemented, and it just needed a snapshot to go through

src/librustdoc/test.rs

@@ -144,10 +144,10 @@ fn maketest(s: &str, cratename: &str) -> ~str {
 #[allow(unused_variable, dead_assignment, unused_mut, attribute_usage, dead_code)];
 ";
     if s.contains("extra") {
-        prog.push_str("extern mod extra;\n");
+        prog.push_str("extern crate extra;\n");
     }
     if s.contains(cratename) {
-        prog.push_str(format!("extern mod {};\n", cratename));
+        prog.push_str(format!("extern crate {};\n", cratename));
     }
     if s.contains("fn main") {
         prog.push_str(s);